CVE-2024-41048 is a vulnerability in the Linux kernel affecting the sk_msg_recvmsg() function within the skmsg subsystem, specifically triggered on Loongarch architecture platforms. The issue arises when a zero-length socket buffer (skb) is processed, which corresponds to a TCP FIN packet sent by the shutdown() system call. In this scenario, the zero-length skb is enqueued with an empty scatter-gather entry (sge) that contains no associated memory page. When sk_msg_recvmsg() attempts to process this skb, it calls copy_page_to_iter() with a NULL page pointer, leading to a kernel panic due to a NULL pointer dereference in page_address(). This behavior is architecture-dependent: on x86 platforms, the NULL page dereference does not cause a panic and thus the bug remained hidden, but on Loongarch platforms it results in a fatal kernel exception and system crash. The root cause is that the zero-length skb is not properly skipped during message reception, causing the kernel to attempt to access invalid memory. The fix involves modifying sk_msg_recvmsg() to detect zero-length skbs and skip the copy_page_to_iter() call, preventing the NULL pointer dereference and subsequent panic. This vulnerability was discovered during BPF selftests involving sockmap_basic tests on Loongarch hardware and is specific to kernel versions around 6.10.0-rc2+ as tested. No known exploits are reported in the wild, and no CVSS score has been assigned yet. The vulnerability is significant because it can cause a denial of service (DoS) via kernel panic on affected systems, impacting system availability and stability.

For European organizations, the primary impact of CVE-2024-41048 is a potential denial of service condition on Linux systems running on Loongarch architecture hardware. Although Loongarch is a less common architecture compared to x86_64 or ARM in Europe, organizations using specialized or emerging hardware platforms based on Loongarch could experience unexpected kernel panics and system crashes when running workloads involving BPF programs or socket message handling, particularly those using TCP shutdown operations. This could disrupt critical services, especially in environments relying on Linux kernel features like BPF for networking or security monitoring. The vulnerability does not appear to allow privilege escalation or remote code execution, limiting its impact to availability. However, the forced kernel panic could cause downtime, data loss, or service interruptions. Since the bug is triggered by specific socket operations, applications or services that perform TCP shutdowns or use advanced socket features may be more susceptible. European organizations with research, development, or deployment of Loongarch-based Linux systems should prioritize patching to maintain system reliability. The vulnerability is less likely to affect mainstream Linux deployments on x86 or ARM architectures prevalent in Europe, but awareness is important for niche or emerging platform users.

1. Apply the official Linux kernel patches that address CVE-2024-41048 as soon as they become available, particularly for kernels running on Loongarch platforms. Monitor Linux kernel mailing lists and vendor advisories for updates. 2. For organizations using Loongarch-based Linux systems, avoid running untrusted or experimental BPF programs or socket tests that could trigger the vulnerability until patched. 3. Implement kernel crash monitoring and automated recovery mechanisms to reduce downtime in case of kernel panics. 4. Conduct thorough testing of network applications that use TCP shutdown calls or advanced socket message handling on Loongarch hardware to identify potential triggers. 5. Engage with hardware and Linux distribution vendors to ensure timely delivery of patched kernels and backports for affected versions. 6. Consider architectural diversity or fallback mechanisms in critical environments to mitigate risks from platform-specific kernel bugs. 7. Maintain up-to-date backups and disaster recovery plans to minimize impact from unexpected system crashes.